ERCP after bariatric surgery--literature review and case report.

Obesity is a disease which has become more prevalent in Romania. Bariatric surgical procedures are among the treatment options for obese patients. Obesity and the metabolic disorders induced by it are risk factors for gallstones formation and their complications. ERCP is a minimally invasive therapeutic procedure indicated in the treatment of choledochal lithiasis and its complications. ERCP is generally considered the most difficult endoscopic procedure from the technical point of view. The authors have proposed to consider the possibility of performing therapeutic ERCP in patients who have undergone bariatric procedures. Literature data are reviewed and the case of a patient treated in a minimally invasive (laparoendoscopic) way for cholecyst and choledocholithiasis after longitudinal gastrectomy is presented.


Pathophysiology and the effects of therapy
Obesity related metabolic imbalances create the premises for gallstone formation. Obesity causes increased synthesis and secretion of cholesterol, leading to the formation of gallstones. Through its different methods, bariatric surgery leads to a significant and rapid weight decrease. Changes of bile composition, incumbent to body mass reduction, consists of a pronounced increase of mucin concentration (18 times) with an increase of calcium ions (40%). These changes lead to a high propensity of bile stones development.
A prospective study conducted by Schiffman and published in 1991 in the Am. J. of Gastroenterology showed that in patients undergoing gastric bypass, significant changes of bile composition are generated, which lead to gallstone appearance in 36% of the cases in approximately 6 months and to biliary sludge in another 13% of the cases. Of the patients who developed gallstones, almost half (41%) are symptomatic [1,2].

Clinical evidence
These data have raised new issues, namely the importance of identifying risk factors for the occurrence of gallstones after bariatric interventions. It was found that traditional risk factors for gallstones appearance are not predictive for the formation of biliary lithiasis after bariatric surgery. In 2009, Li published in Surgical Endoscopy the results of a study that identifies the reduction of body mass with at least 25%, as predictive for the formation of gallstones after different bariatric procedures in [3].
Thus, the necessity to develop some strategies for the prevention and treatment of biliary lithiasis and its complications has come into prominence. Some were repeatedly evaluated:   Each of the different modalities according to which the transoral access into the biliary ducts is achieved has advantages and disadvantages and these are summarized in Table 1. In 2011, Lars Aabakken presented, in Munich, the results of a multicentre study including 129 patients with modified anatomy secondary to a bypass procedure with a "Y long loop", 69 of them having a gastric bypass. To these 156 ERCPs have been performed. The techniques used were: • ERCP by double balloon enteroscopy • ERCP by simple balloon enteroscopy • ERCP by spiral enteroscopy Duodenal access had a success rate of 69%, 72% and 74% respectively, with small differences between the three techniques. When duodenal access was accomplished, the success rate of ERCP was of of 88%, with rather similar figures for the different techniques: 63%, 60%, 65%.
Complications were registered in 12% of cases (16 of 129 patients) and their range was similar to the general complications of ERCP: acute post-ERCP pancreatitis, papillary bleeding or retroperitoneal duodenal perforation [7].
Because transoral access is difficult in patients with gastric bypass, an alternative method was imagined -transgastric access (through the distal stomach). The method implies laparoscopic assistance or the placement of a gastrostomy tube into the distal stomach at the moment of the primary operation (the tube is abandoned in the subcutaneous space, is radiologically traceable and will help a percutaneous access in the distal stomach in the postoperative period). This technique was originally described by Baron [4] and Fobi [5] in 1998 and recently reiterated by Gutierez [6].
The transgastric access allows the use of an endoscope having lateral view and of standard accessories, the approach to the major papilla being done in the conventional way. The two modalities of transgastric access (laparoscopically assisted and through a gastrostomy tube) have advantages and disadvantages summarized in Table 2. The endoscopic transenteric access is a difficult approach with just a few case reports in the medical literature [8,9] and the laparoscopic exploration of the common bile duct does not have any peculiarities in obese patients with bariatric operations.

Case report
We present below the case of a 57-year-old female patient with morbid superobesity and nonsymptomatic gallstones.
The CT examination showed the uncomplicated gallstones and a common bile duct of 7 mm, without images of choledochal lithiasis.
The patient was scheduled for sleeve gastrectomy and presumed cholecystectomy if allowed (reasonable anesthetic and surgical risk, expeditious and uncomplicated bariatric operation). These conditions being fulfilled, the cholecystectomy was performed. A rather large cystic duct was observed and an intraoperative transcystic cholangiography was done, which detected the presence of multiple choledochal stones.
Because of the recently performed stapled anastomosis, the endoscopic treatment was delayed under the protection of an external transcystic biliary drainage.
Two weeks later, a transoral ERCP was done with an easy duodenal access but a papillary one inconveniently influenced by a interposed duodenal diverticula. A sphincterotomy with stones extraction and control cholangiography was performed. The uneventful postoperative course permitted the withdrawal of the external biliary drainage 24 hours later.

Conclusions
The presence of biliary lithiasis is frequent in obese patients and its natural course is similar to that in the general population. The area of complications is the same and they are not directly linked to the presence of symptoms. Analyzing the therapeutic strategies for the prevention of complication and taking into account the risk/benefit ratio, it was agreed that the conduct to be followed is that which involves the performance of a laparoscopic cholecystectomy with bariatric surgery only for patients with symptomatic lithiasis.